I am convinced even had Reddit kept the old design, it would still suck now, because any site focused on a universal demographic will inevitably get most people coming in on mobile, and mobile inherently discourages longform text and encourages images.
I find that for various special-interest, hobbyist forums, you need some kind of friction to prevent low-effort posters from taking over, and ensure more people are participating from desktop/laptops. I have gone back some phpBB fora I have neglected after Reddit's ascent, and while there are fewer people around and they skew older, I am amazed at how substantial and competent discussions are compared to their subreddit counterparts.